Medicinal spa created with the discharge from a geothermal energy plant.

The intricate stonework of Machu Picchu serves as a testament to Incan engineers.

An exquisite tunnel of cascading flowers.

The mysterious, fantastical woodland inspiration for "The Lord of the Rings."

The vast, legendary catacombs hold secrets much stranger than stacked bones.

This unattributed sculpture in Amsterdam is hiding in plain sight.

The Bloemen Route, or “Flower Route”, stretches 25 miles through prime Dutch tulip country as a result of “tulip mania,” the world’s first economic bubble.

For the holidays, the tallest broadcasting tower in the Netherlands turns into one of the world's tallest Christmas trees.

Devious political maneuvering and four ancient, working telescopes are central to the world's second-oldest observatory.

Survival capsules find a second life as a unique hotel.

Hidden within a Netherlands crater is a stone bed that lets those who lie in it see the sky as a curved surface.

“And the Lord said unto Johan, build for thee an ark for the end of the world is approaching.”

Peek through a transparent pyramid and drink in the mountain made of books.

Birthplace of the "Cat in the Cradle" and a cluster of iconic, original windmills that let the Dutch tame the seas.

Wind power station for making famous Ketel One vodka.

Built by crowdsourcing, this wooden foot bridge saved a part of Rotterdam that was languishing in wait of city funding.

These slanted cubic abodes are a creative if odd solution to a zoning pickle.